In the manufacturing steps of rubber products such as tires, a belt-like belt member made of a plurality of steel cords disposed side by side at a predetermined cord angle and covered with a rubber is used. The belt member is formed by cutting disposed steel cords side by side covered with a rubber at the predetermined angle set in accordance with the cord angle at a predetermined length, and bonding together the plurality of members that are cut (for example, see Japanese Unexamined Patent Application Publication No. 2009-226817A). The belt-like belt member is wound around a forming drum and formed in a cylindrical shape. Further, a tread rubber forming a tire tread is formed cylindrically by a belt-like unvulcanized rubber being wound around the forming drum.
When the belt-like belt member and the belt-like unvulcanized rubber are wound around the forming drum in meandering form, a cylindrical member having distortion in the drum width direction is formed. Manufacturing tires using the distorted cylindrical member makes it difficult to ensure consistent quality. Thus, it is important to accurately wind the belt-like member around the forming drum without meandering to form the belt-like member in a cylindrical shape.